'''
while循环语句
形式：while 条件:
       语句
'''
#1到30之间3的倍数
n = 1
while n <= 30:
    if n % 3 == 0:
        print(n)
    n = n + 1
print('*' * 20)
#1到20之间的累加和
sum = 0
i = 1
while i <= 20:
    sum += i
    i = i + 1
print(sum)